The American Rescue Plan Act of 2021 has passed Congress and was signed by the president. The new law makes changes to the Internal Revenue Code, affecting single employer and multiemployer defined benefit (DB) plans, with optional retroactive dates. This bulletin details the provisions on amortization of plan debt and interest rate calculations. The provisions provide additional flexibility to plan sponsors by permitting a longer time over which they can amortize the DB plans’ debt, and by recasting the deficit using modified interest rates to calculate the liabilities. The bulletin concludes with what the changes mean for plan sponsors.